Trick to resize non-square photos for Instagram without using an extra app

I was trying to upload a new photo to Instagram, but the image was too long width-wise to fit in Instagram’s “square”. Instagram doesn’t let you zoom out on a photo, so I knew I basically needed to add some extra white space to my photo so it would be square again. You can download apps that will do this for you, but the quick-and-easy method is simply to open your photo in the native Photos app on your phone and then take a screenshot of your screen (on iOS devices, push the Home button and the Power button at the same time. For Android devices, push and hold the Power button and the Volume Down button for 1-2 seconds until a brief white flash appears). Now you should be able to easily upload a cropped version of your screenshot into Instagram!